Casting tenders mix iron trade terms, standards numbers and waterworks slang. This page defines the ones you will meet in Ontario and Atlantic Canada specs, alphabetically, with links to the DomCast pages they map to. Load and material numbers come from the cited standards, not from any DomCast SKU; certification for a specific casting is confirmed per SKU at quote.
A to C
AASHTO M306
The AASHTO specification for drainage, sewer, utility and related castings. It sets a proof load of 40,000 lb for H-20 traffic and 50,000 lb for H-25, applied through a 9-inch by 9-inch bearing pad, and names grey iron per AASHTO M105 / ASTM A48 Class 35B as the baseline material. Full breakdown on the AASHTO M306 guide.
Adjustment ring (grade ring)
A ring set between the top of a maintenance hole or catch basin and the frame to bring the frame to finished grade. OPSS.MUNI 407 defines adjustment units as "circular and rectangular units used between the structure and the frame to adjust the elevation of the frame for grates and covers." Concrete, rubber (OPSS 1853) and HDPE (OPSS 1854) versions exist.
ASTM A48
The ASTM specification for grey iron castings, classed by minimum tensile strength of a separately cast test bar. Class 35B means 35 ksi (35,000 psi) minimum; the letter is the test bar size. It is the material AASHTO M306 calls for.
ASTM A536
The ASTM specification for ductile iron castings. Grades read tensile-yield-elongation, so 65-45-12 means 65 ksi tensile, 45 ksi yield and 12% elongation.
Bicycle-proof grate
A catch basin grate whose slot pattern will not trap a bicycle tire. Ontario has cancelled at least one older grate drawing on these grounds: Toronto's OPSD revision sheet lists OPSD 400.01, a 1987 dished square grate, as "cancelled due to bicycle safety concerns." OPSD 400.100 is the current flat grate with perforated openings. Specify the drawing number your municipality has adopted rather than the phrase. See grates and drain covers.
Catch basin
The structure at the curb that takes runoff into the storm sewer, with a sump to trap grit. Ontario specifies the frame and grate by OPSD number, e.g. OPSD 400.020, "Cast Iron, Square Frame With Square Flat Grate For Catch Basins, Herring Bone Openings." DomCast lists these under catch basins, e.g. 400.020.
Catchbasin
Catch basin written as one word. Both spellings appear in Ontario tenders and in DomCast product names (dished overflow catchbasin, flat catchbasin, V-type catchbasin).
Cleanout
An access point on a sewer lateral or drain, closed with a small frame and cover so the line can be rodded without digging. Sized to the pipe (4", 6", 8", 10") and often gasketed. See DF44 and DF66I.
Clear opening
The unobstructed diameter or width through the frame with the cover off. It is the dimension to check when substituting frames, not the casting's outside dimension.
C.S.P.
Corrugated steel pipe. Its outside diameter differs from concrete or HDPE pipe of the same nominal size, so a 24" C.S.P. grate is a different casting from a 24" concrete grate. DomCast standard grates are listed by pipe type, e.g. DF2044A (12" C.S.P.).
CTS
Copper tube size. The outside diameter is the nominal size plus 1/8", so 1" CTS is 1.125" OD. Water services and curb stops are sized CTS. See the pipe OD chart.
Curb box
The vertical cast iron sleeve from the curb stop up to grade, with a small lid at the surface. Also called a service box. A stainless steel rod inside lets a crew work the curb stop with a key. See service curb boxes, e.g. DF907.
Curb inlet
A catch basin opening in the face of the curb, instead of or alongside the grate in the gutter. It keeps taking flow when the grate is blocked.
Curb stop
The shut-off valve on a water service between the main and the building, near the property line, operated from above ground through a curb box.
D to H
DIPS
Ductile iron pipe size. An OD system for ductile iron pipe and for HDPE made to match it. DIPS and IPS pipe of the same nominal size have different ODs, so fittings are ordered by sizing system. See the pipe OD chart.
Drain cover
A slotted or perforated cover on a floor, yard or area drain. Smaller than a road grate and often gasketed. See grates and drain covers.
Ductile iron
Cast iron in which the graphite forms spheres rather than flakes, giving tensile strength and elongation grey iron lacks. Specified to ASTM A536.
EN 124
The European standard for manhole and gully tops. Load classes are named by test load in kilonewtons: A15, B125, C250, D400, E600 and F900. D400 (400 kN) is the carriageway class. It appears in Canadian tenders mainly when a product is dual-marked.
Frame and cover
The two-piece casting on a maintenance hole: the frame sits on the structure or adjustment rings, the cover sits in the frame. Frame and grate is the catch basin equivalent. See manhole frames and covers.
Gasketed / airtight cover
A cover with an elastomer gasket in the seat so it seals against the frame. Used on sanitary sewers to hold back odour and at low points to cut surface inflow.
Grey iron
Cast iron with flake graphite, the traditional municipal casting material. Specified to ASTM A48 or AASHTO M105. Spelled "gray iron" in US standards.
H-20
An AASHTO highway loading. NPCA gives it as a 32,000 lb axle or a 16,000 lb wheel load. H-20 is a design load, not a proof load; AASHTO M306's proof load for H-20 service is 2.5 times the wheel load, 40,000 lb. H-25 is the heavier case (20,000 lb wheel).
HDPE
High-density polyethylene. It shows up as a pipe material with its own grate sizes and as the material for moulded adjustment rings (OPSS 1854).
I to O
IPS
Iron pipe size. The OD is fixed per nominal size and differs from the nominal number, e.g. 2" IPS is 2.375" OD. Steel pipe and IPS-sized HDPE use it. See the pipe OD chart.
Lockable cover
A cover held to its frame by bolts, a cam or a latch so it cannot be lifted without a tool. OPSS 1850 covers locking devices alongside frames, grates and covers.
Maintenance hole (manhole)
The Ontario term for a manhole. Ontario renamed manholes to maintenance holes in the mid-1990s, and OPSS and OPSD use the term throughout, e.g. OPSS.MUNI 407, "Construction Specification for New Maintenance Hole, Catch Basin, Ditch Inlet, and Valve Chamber Installation." Product names industry-wide still say manhole. See manhole frames and covers.
Mechanical joint (MJ)
A bolted joint for ductile iron pipe, fittings, valves and hydrants: a rubber gasket is compressed between pipe and bell by a gland pulled up with T-bolts. Covered by AWWA C111/A21.11, which sizes the joint for pipe 3" through 24".
MJ bolt pack
The bagged set of T-bolts and nuts for one mechanical joint, sized to the fitting. Sold in plain alloy, coated and stainless versions. See MJ bolt packs, e.g. CMJBP04 and CMJBP04SST.
Municipal castings
The iron castings a municipality buys for roads, sewers and water: manhole frames and covers, catch basin frames and grates, curb inlets, valve boxes, curb boxes, meter vaults, cleanouts, trench grates and tactile plates. AASHTO M306 and OPSS 1850 are the specs most often written against them.
OD (outside diameter)
The measured outside diameter of a pipe, as opposed to its nominal size. CTS, IPS and DIPS give different ODs for the same nominal number, so OD decides whether a grate or fitting fits. The pipe OD chart lists them side by side.
OPSD
Ontario Provincial Standard Drawings. The 400 series covers frames, grates and covers, and Ontario tenders name castings by OPSD number, e.g. OPSD 401.010, "Cast Iron, Square Frame With Circular Closed Or Open Cover For Maintenance Holes." DomCast uses the OPSD number as the SKU where a product is patterned on the drawing, e.g. 401.010. Drawing conformance is confirmed per SKU at quote.
OPSS
Ontario Provincial Standard Specifications, the written companion to OPSD. OPSS.PROV is for Ministry of Transportation contracts, OPSS.MUNI for municipal ones. A casting buyer meets OPSS 407 (new installation), OPSS 408 (adjusting or rebuilding) and OPSS 1850 (frames, grates, covers and gratings).
P to W
Perforated cover
A maintenance hole cover with holes through it to vent the sewer and admit some surface water; OPSD 401.010 calls it an "open" cover versus the solid "closed" cover. Used on storm sewers, not sanitary. See 401.010B (perforated) and 401.010 (solid).
Proof load
A test load applied to a finished casting seated in its frame, which it must carry without cracking or taking a permanent set. It exceeds the design wheel load by a safety factor; under AASHTO M306 that is 2.5 times, giving 40,000 lb for H-20. It is a structural test, not a material certificate.
Seating surface
The ring of contact between cover and frame. A cover that rocks in its frame is the main source of noise and wear, so specs may call for a machined seat or rubber insert.
Sewer grate
Everyday name for a catch basin grate. Engineers write "catch basin frame and grate" and cite an OPSD number. See catch basins.
Speed ring
DomCast's name for LADTECH moulded HDPE adjustment rings, listed under LADTECH/DOMCAST speed rings. LadTech moulds them from recycled HDPE as an alternative to concrete grade rings. Flat and sloped, several thicknesses, e.g. LD2424F125. Load rating is confirmed per SKU at quote.
Tactile plate
A cast iron plate with truncated domes, set into a curb ramp or platform edge as a tactile walking surface indicator for people with low vision. Ontario's AODA Design of Public Spaces Standards require TWSIs at new or redeveloped curb ramps and depressed curbs at pedestrian crossings. See cast iron tactile plates, raw or powder coated, e.g. ADV2424Y.
Valve box
A telescoping cast iron sleeve over a buried water main valve so the operating nut can be reached from the surface. Named by top diameter and how the sections join (4 1/4" slide, 5 1/4" screw, 5 1/4" slide). See valve boxes, e.g. DF6902.
Water meter vault
A pit or vault at grade over a water meter, with a frame and lid on top. Residential versions are a meter pit with a frost lid; larger ones are multi-piece with a bonnet and frost cover. See water meter vaults, e.g. DFWV14.
Missing a term? Ask us and we will add it. Certification and drawing conformance for any DomCast casting are confirmed per SKU at quote.
Request a QuoteSources: https://municipalcastings.org/resources-articles/aashto-standards/ · https://precast.org/blog/manhole-frame-and-cover-load-bearing-definitions/ · https://www.library.mto.gov.on.ca/SydneyPLUS/TechPubs/Download.aspx?template=TechPub01&field=Attachment&record=c41a1516-e87d-4629-a1c7-bd982343cfad&lang=en-US · https://tcp.mto.gov.on.ca/sites/default/files/2022-09/OPSS%20PROV%20408.pdf · https://www.roadauthority.com/Standards/?id=46513442-fd6c-4363-bbbe-47063555e264 · https://www.roadauthority.com/Standards/?id=222755be-9d2c-48af-92fc-9e2ff960768a · https://www.roadauthority.com/Standards/?id=9e6f8ac3-f06e-4a24-80e6-4b92a9d66d18 · https://www.roadauthority.com/Standards/?id=227604fe-2f69-48c1-b4e1-aaa17cee77b5 · https://www.toronto.ca/wp-content/uploads/2017/11/977b-ecs-specs-piperevs-Revision_Sheet_6_sw.pdf · https://www.uxbridge.ca/public/download/files/311296 · https://ccppa.ca/standardized-maintenance-holes/ · https://www.dura-bar.com/getmedia/40711cc9-14bf-448c-92b2-40644500870d/astm-a48-gray-iron-grades-0819.pdf · https://www.pentictonfoundry.com/news/ductile-iron-data-sheet-astm-a536-65-45-12/ · https://www.jdpipes.co.uk/knowledge/manhole-covers/bsen124-explained.html · https://blog.boshart.com/differences-between-iron-pipe-size-nominal-pipe-size-copper-tube-size · https://en.wikipedia.org/wiki/Iron_pipe_size · https://www.viega.us/en/resources/Blog/iron-pipe-Size-vs-copper-tube-sizes.html · https://en.wikipedia.org/wiki/Curb_box · https://www.aymcdonald.com/en/news/2023/April/kick-your-curb-stop-questions-to-the-curb--190 · https://store.awwa.org/AWWA-C111-A21.11-23-Rubber-Gasket-Joints-for-Ductile-Iron-Pressure-Pipe-and-Fittings · https://ladtech.com/hdpe-manhole-adjusting-rings-product-overview/ · https://www.toronto.ca/services-payments/streets-parking-transportation/sidewalk-tours-wayfinding/accessible-streets/accessibility-standards-legislation/ · https://www.tactilesolution.ca/blog/a-comprehensive-guide-to-canadian-regulations-on-tactile-walking-surface-indicators